Abstract : Due to the recent demand for data concerning radiofrequency (RF) hazards to man, extensive information is now needed on the normal metabolites of experimental animals exposed to various RF fields. The metal content of blood plasma is known to respond to various thermal environments. This response is thought to be the primary means by which RF fields affect most biologic systems. X-ray fluorescence has recently been shown to be a feasible technique, by means of using lithium-drifted silicon or germanium solid-state detectors, for the simultaneous determination of several metals in biologic samples. This report describes the source arrangement and calibration of such a fluorometer, as well as the calibration of the solid-state detectors in the 3.5 Kev to 3.5 Mev energy region. Also included is the application of the completed apparatus to x-ray fluorescence analysis of biologic systems. (Modified author abstract)